Long Distance Voyager

By The Metric Maven

Bulldog Edition

When it comes to distance, the larger metric prefixes are generally neglected. Astronomers feel justified in using Astronomical Units to describe distances within the solar system. When distances become large enough, the ubiquitous light-year is then employed with great relish and awe. One of the arguments offered for the absence of the larger metric prefixes in astronomy, is that the distances are just too large, and the metric system is overwhelmed. The distances are just too astronomical for the metric system to handle!—or even convey their vastness! Generally, this manner of argument masks a provincial desire by a specialty of engineering or science to have its “own” special measurements. It is also stated that people can only relate to Km and smaller metric measures because the other distances are outside of their everyday experience.

I have had the privilege of working with some incredibly talented engineers, including the Engineer, who designed the high gain dish antenna which resides on the front of the Voyager spacecraft. His name is Michel, and I once shared an office with him. The Voyager antenna would at one time have been within millimeters of Michel, it was then moved about 4000 Kilometers away from him so it could be launched into space on September 5, 1977 (1977-09-05). It ascended from our planet, which has a circumference of 40 Megameters. Michel’s antenna then passed the orbit of the moon which is about 384 Megameters from Earth. One could argue that the Voyager spacecraft was now in the realm of the solar system. At that point, its distance from the sun might be a more meaningful reference point to describe its distance from us. The Earth is approximately 150 Gigameters from the sun.

Gigameters is a useful length to describe the distances of our planets from the sun, as well as the current location of the Voyager spacecraft (2014-04-04). Michel’s antenna is part of the singular human-constructed object we call Voyager 1, and is further away from the Earth than any other space probe in history—and likely to remain so. Despite the fact that Voyager is now beyond our solar system, its distance is still readily describable in terms of Gigameters. Below is a table of planetary distances and Voyager 1 and 2:

I don’t recall any astronomers ever using Gigameters in school or on television, even though it is a convenient unit. Astronomers define their own “yardstick” which they call an astronomical unit. This astronomical unit is defined as the distance from the earth to the sun, therefore 1 AU = 150 Gigameters. I don’t see why modern astronomers, by which I mean astronomers who have been born after 1960, don’t use Gigameters instead. The prefix Giga was officially adopted in 1960. A Gigameter is certainly as convenient of a unit as an AU, and it’s tied to the meter, which is the universal measurement length used by science, and by 95% of the worlds population. When a person, even an American, sees the symbol Km, they see kilometers. The lack of use of the designation Gm for Gigameters by astronomers makes it unfamiliar and seemingly awkward. It is only the lack of general use which makes this so.

When Astronomers begin to describe distances outside of our solar system, they generally turn to another unit they coined which is unique to astronomers—the light-year. Wikipedia gives the definition of  a light-year as:

1 light-year     = 9460730472580800 metres (exactly)

This is where, if I were forced to write it in meters, I would use the three digit space convention to parse it. The three digit grouping allows a person to identify the appropriate metric prefixes with ease:

1 light-year     = 9 460 730 472 580 800 metres (exactly)

This expression allows one to immediately recognize the metric prefixes as one moves from right to left as: one, Kilo, Mega, Giga, Tera, Peta, and determine that 1 light-year = 9.461 Petameters (Pm). In my view the light-year is more of a “gee whiz” measurement metaphor than an actual length. It is like the kilowatt-hour. There is a metric prefix which is of sufficient magnitude to describe distances which have magnitudes in terms of light-years and it is Peta. The hypothetical Oort cloud is believed to be about 7.5 Petameters away, which when compared with stars, it not  far away.

Almost everyone knows that alpha-centari is the star closest to Earth (other than the sun). It is 4.366 light-years distant. This is 41.4 Petameters. So even when we are discussing the distances to stars, there is a sufficient metric prefix. The light year is not required, at least not after 1975, when Peta was adopted as a metric prefix. Here is a list of nearby stars, and a more distant one also in Petameters:

Constellation of Orion Betelgeuse is the upper left star which is about 6 Em from Earth. Rigel is on the lower right and about 8 Em from Earth — Click to enlarge                    (Wikimedia Commons)

Betelgeuse is a red giant which is in the upper left corner of the constellation Orion. On a clear night in Montana, when I lived far away from the city lights, I could clearly see its red color. Stars beyond Betelgeuse are at distances that may require the introduction of another metric prefix.  This would be the prefix Exa.  One could categorize stars which are “near” earth as those up to 1000 Pm and those beyond 1 Em (Exameter) as “far away” stars. This would make Alpha-Centari, Barnard’s Star and Sirius all nearby stars. Far away stars would include Betelgeuse (6.1 Em) and Rigel (7.7 Em). The farthest currently known star which is still inside of the Milky Way Galaxy is  UDF 2457. It is 558 Em distant.

When we approach the dimensions of the Milky Way Galaxy, we may want to describe the distances from the galactic center. The diameter of our galaxy dwarfs the distance from the sun to Betelgeuse. It is 1 000 000 Petameters across or, shifting metric prefixes, is approximately 1 Zettameter (Zm) in extent. From this information, we know that no star within our galaxy is more than a zettameter away.

The Andromeda Galaxy is 24 Zm from Earth and is visible with the unaided eye.                      (Wikimedia Commons)

Interestingly, we can directly see a distance which is much farther than the dimension our galaxy with the unaided eye. The nearest spiral galaxy is Andromeda, and it can be viewed with the “naked eye.” The Andromeda Galaxy is 2 540 000 light-years away or approximately 24 Zettameters (Zm). This is rather close. It is only 24 times the diameter of our galactic disk. The Andromeda galaxy is expected to collide with our Milky Way Galaxy in 3.75 billion years and form a large elliptical galaxy. Andromeda is not the nearest galaxy overall. The Sagittarius Dwarf Elliptical Galaxy is actually a satellite Galaxy of the Milky Way, that is, it orbits our galaxy. It is only 0.77 Zettameters from our galaxy (or 766 Exameters). This places it just a couple of hundred Exameters beyond the farthest known star within the Milky Way Galaxy.

Here is a short list of local group galaxies which are over one Zettameter away:

The Sombrero Galaxy is 265 Zm from Earth (Wikimedia Commons)

Sextans B is near the end of what is known as the local group of galaxies. The local group encompasses a diameter of about 100 Zettameters (Zm). Clearly there are lots of galaxies which are further away, so which one is the farthest known? The current candidate for the furthest galaxy is MACS0647-JD which is a whopping  125 825 Zettameters (Zm). We can see that we are well beyond a 1000 difference. Has the metric system let us down because of this astronomical distance? No, it has not, at least not since 1991. In 1991 both the Zetta prefix, and the Yotta prefix were added. The Yotta prefix allows us to write the distance to the farthest confirmed galaxy as 126 Yottameters (Ym). The end of the observable universe is approximately 435 Yottameters (Ym). The diameter of the universe is 870 Ym. Astronomical distances do not crush the metric system. There is no need for astronomers to resort to a light-year or AU or parsecs to describe astronomical dimensions. The metric system can in fact be useful to classify astronomical distances. For instance:

click to enlarge
Neil deGrasse Tyson — Host of Cosmos

The latest incarnation of Cosmos has been interesting to watch, but I can only wince when I hear Neal deGrasse Tyson use miles, billions of kilometers, astronomical units, and light-years to describe the cosmos. This archaic measurement usage seems like a lack of respect for the metric system on the part of the Cosmos producers. It is 34 years after the original series was aired. When the original Cosmos aired, the Zetta and Yotta prefixes had not been added to SI. One could see why metric might not have been invoked. Indeed, SI was not large enough to encompass the universe, but like the universe, it expanded. Unfortunately, the root cause for the lack of the metric system in Cosmos could possibly have an even less desirable origin—it could just be unawareness. It is even possible it is the product of a culturally encouraged unfamiliarity. This culturally sanctioned ignorance, if that is the root source, was fortified at the same time as the first airing of Cosmos in 1980. It was in that year that Ronald Reagan quashed any possibility of measurement reform in the US, by disbanding the metric board. This disbanding was an attack on modernity and efficiency, mantled in a red herring of cost savings. It was a narcotic of intellectual flattery perpetrated by a cultural embargo, which has numbed the minds of the American public to the spectrum of metric prefixes, and in turn, it has cost lives. If there is another edition of Cosmos 34 years from now, I can only hope, that by then, it uses the metric system.

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Related essay: Neil deGrasse Tyson and The Metric System

This essay was edited on 2016-10-15 to conform with The Elements of Bile.

The Lone Star Country

By The Metric Maven

Bulldog Edition

In my second anniversary blog I made a short statement about why I thought Liberia had not adopted the metric system. I did not think it would be controversial in any way, but to my surprise some non-US residents of the world seemed to take issue with my summation:

Liberia: settled by expatriate former slaves from the US. Many Liberians apparently still think of themselves as tied to America, so it’s not shocking they are also not metric.

Liberia, has always been a curiosity for me. It first entered my consciousness somewhere about 1970 or so. I watched a report on CBS (I think it was 60 minutes) about Liberia. It was mind boggling. The town they showed (I assume it was Monrovia) looked like my own hometown. The houses looked the same, the mail boxes looked the same, the postal uniforms were the same, people spoke English, but everyone was black. It made quite an impact on me. Liberia would later become known as the place for U.S. ships to register to avoid U.S. safety regulation. In the 1980s I was saddened to hear about the civil war there.  After that, I really didn’t know what happened. Perhaps the people from outside the US knew something I didn’t?  Had Liberia changed so much that I could not make the assumption they still related as Americans?

I looked for a current history of Liberia, and was rewarded when I found Another America: The Story of Liberia and the Former Slaves Who Ruled It, by James Ciment. It was published in 2013. The future Liberians arrived in Africa on what the author called The Black Mayflower. The name of the ship was The Elizabeth. In a document, apparently lost to history, there was a version of a Mayflower Compact. When they arrived, Ciment states: “[Lott] Carey was one of the first colonists to recognize that the colonists, soon to be Liberians, were a tiny and largely friendless people in a big and hostile land.” The local Africans referred to the colonists as “Black White men.” These men would create a Declaration of Independence which began “We, the people of the Republic of Liberia were originally the inhabitants of the United States of North America.” They wrote a Constitution which largely ignored the local population, and elected their first President. The capital, Monrovia, is the only one named for the elected leader of another country.

Liberians would later lose a considerable amount of their territory to British and French ambitions. As they saw the US as harboring no designs on territory in Africa, America would often become the trusted broker in disputes. At one point Buffalo Soldiers from the US were dispatched to Liberia as part of a loan guaranteed by the American government. This caused some stress between the Liberians and the US.

By World War I the Liberians had begun to look toward Europe, and Germany in particular, for trade. Ciment relates:  “But when the United States entered the war in April 1917, it pressured Monrovia to sever ties with Berlin, which, by the early twentieth century, had become the country’s leading trade partner. President King felt that his nation was owed something for this act of loyalty.” Unfortunately, the US did not compensate Liberia for doing so.

In 1924 Harvey Firestone, decided Liberia would be a great place to get rubber. Firestone pushed through a deal in which: “Liberia would remain a virtually wholly owned subsidiary of Harvey Firestone until its economic expansion after World War II….”

Liberia had been founded to do missionary work in Africa, and so almost all its schools were seminary schools where “They learned little that was modern or practical—little that might prove useful in business and industry—a constant complaint of domestic and foreign pedagogical reformers then and since.” What they did produce in excess were Lawyers.

After World War II the Liberians continued to be diplomatically close to the US:

The Barclay administration, ever suspicious of white outsiders, put up obstacle after obstacle to a potential deal. “I am of the opinion … that only an American enterprise will succeed, as only they can recon with the collaboration of the Liberian authorities.”

Indeed this proved to be true, and cash began to flow into Liberia in the 1950s and 1960s. There was an improvement in the everyday lives of some Liberians:

…but Monrovia’s well-connected “big-men” benefited as well, While they were chauffeured in American sedans to desk jobs at foreign subsidiaries, their wives cruised the aisles at the White Rose Supermarket, lured by advertisements boasting “a fresh supply  of goods from the U.S.”

Unfortunately the well-off had grown rich, but the poor remained poor. This would precipitate stress in Liberian society. The tight connection with the US continued in this period. Ciment indicates that  “….in Liberia, having been “abroad” always meant having been to America, and was a coveted status marker….”

In 1980 there was a coup. It ended the 133 year rule of the Americo-Liberian elite. What happened during this time is still uncertain and clouded in mystery. Even basic information is not known about the principals involved, and who did what. When the coup did occur, the Americo-Liberian elite who could, fled the country. Many ended up in Virgina, Maryland and New York. The Liberian civil war and its aftermath were horrific, and only in recent years has any semblance of stability reestablished itself.

In my view, Liberia has remained very much the Lone Star Country. The talk of becoming metric in the US ended in 1980 with the disbanding of the Metric Board by Ronald Reagan. Liberia was and is culturally tied to the US, and so, if the US was never to become metric, it would make sense that Liberia saw no reason to change.

But what do Liberians think of the US currently?  In his preface James Ciment offers these observations:

I was greeted warmly. Having never been the subjects of Western imperialists, Liberians evince little animus toward white people. They also genuinely like Americans. In the interviews, I sensed that many felt we were practically kin, although the sentiment always seemed tinged with disappointment.


The kinship contemporary Liberians of all backgrounds felt with Americans had deeper and more meaningful roots than I—and perhaps even my interviewees—had ever imagined.

James Ciment’s book, Another America, does not mention the metric system. I spoke by phone with James Ciment on 2014-03-25. The question as to why Liberia has remained non-metric had not occurred to him. He stated that the maps he had when he visited Liberia were old, but as he recalled they were in miles. Liberia’s neighbors are all metric. I asked him if it was because the Liberians see themselves as Americans, and in solidarity retained Ye Olde English measures. Ciment’s answer was short and simple: “Yes.”  He added that another aspect is the political and legislative inertia there. Ciment indicated there is not a lot of signage in Liberia these days.

Climent verified that in the 1960s Liberia was richer and better off than its  neighbors. When I related my recollection of a 60 minutes story about Liberia and how everything looked like the small town from which I came, he confirmed it. Back in the 1960s-1970s it looked like the US. There are still houses in Liberia that look like they have been transported from Alabama to Africa.

The measurement system used in Liberia was transported from America to Liberia as well. It remains there, in the Lone Star Country, probably waiting for the United States to become metric—if it ever does.

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